SHORT ANSWER TYPE QUESTIONS
Q. 1. What do you mean by air pollution?
Ans. When air is contaminated by unwanted substances which have a harmful effect on both living and non-living things, it is referred to as air pollution.
Q. 2. Name the pollutants produced by vehicles.
Ans. Vehicles produce high levels of pollutants like carbon monoxide, carbon dioxide, nitrogen oxide and smoke.
Q. 3. What is smog?
Ans. A thick fog like layer in the atmosphere, especially during winters is known as smog.
Q. 4. What is acid rain?
Ans. Sulphur dioxide and nitrogen dioxide react with water vapour and form sulphuric acid and nitric acid. This acid drops down with rain, making the rain acidic. This is called acid rain.
Q. 5. What do you mean by Marble cancer?
Ans. Acid rain corrodes the marble of monuments. This phenomenon is called Marble cancer.
Q. 6. Write full form of CNG and LPG.
Ans. CNG—Compressed Natural Gas LPG—Liquefied Petroleum Gas
Q. 7. What is Greenhouse effect?
Ans. The reflected sun rays are trapped by the earth atmosphere. The trapped radiation warms the earth. It also warms the green house. This is called Greenhouse effect.
Q. 8. Describe global warming.
Ans. The increasing population and human activities cause the increase in the carbon dioxide in the atmosphere. CO2 is a warm gas, which increases the temperature of the earth’s atmosphere. This is called global warming.
Q. 9. Write some effects of global warming.
Ans. The Following are the effects of global warming:
(i) It affects the green house.
(ii) The Gangotri glacier in the Himalayas has started melting.
(iii) It causes flood on earth.
(iv) It increases the temperature in the atmosphere.
Q . 10. What is water pollution?
Ans. The mixing of harmful substances such as sewage, toxic, chemicals, salt, etc. with water is called water pollution.
Q . 11. Write the causes of air pollution.
Ans. Causes of air pollution:
(i) Emitting smoke by forest fire.
(ii) Poisonous gases expelled by the various industries.
(iii) Poisonous gases emitted by vehicles.
(iv) Smoke and dust arising due to human activities.
Q . 12. How is acid rain caused?
Ans. Different industries produce sulphur dioxide and nitrogen dioxide. Those gases react with water vapour and form sulphuric acid and nitric acids. These acids fall on earth with rain and cause acid rain.
Q . 13. What is ozone? How is it helpful for our environment?
Ans. Ozone is a layer of gases around the earth. It is tri-atom of oxygen atom. It protects the earth from the ultraviolet rays of the sun. The ultraviolet rays cause many disease and damage to our earth. Thus ozone layer is helpful for our environment.
Q . 14. How does water get polluted?
Ans. Water gets polluted when unwanted and harmful chemical substances are added to the water. Untreated sewage and garbage is added to water resources to pollute water.